Crossword puzzle clue "provide missing info and what four clues do to their answers"

Provide missing info ... and what four clues do to their answers

What this puzzle's four missing clues spell, in order

Word needed to be added to 12 appropriately placed answers in this puzzle for their clues to make sense

What seven puzzle answers are with reference to abbreviations in their clues

What's hidden in answers with an apt "#" in their clues

Julian Assange's controversial website, and a hint to what's missing from this puzzle's four longest answers

Role played by each of four actors in the year indicated in their clues

Item missing in this puzzle's theme that's absent as well in the fill and clues